FlightTask: correct activate() doxygen comment

src/lib/flight_tasks/tasks/FlightTask/FlightTask.hpp

@@ -77,7 +77,7 @@ public:
 
 	/**
 	 * Call once on the event where you switch to the task
-	 * @param state of the previous task
+	 * @param last_setpoint last output of the previous task
 	 * @return true on success, false on error
 	 */
 	virtual bool activate(vehicle_local_position_setpoint_s last_setpoint);